;doc: update command help

hledger/Hledger/Cli/Commands/Balance.txt

@@ -35,6 +35,7 @@ balance can show..
 -   or value of balance changes (-V)
 -   or change of balance values (--valuechange)
 -   or unrealised capital gain/loss (--gain)
+-   or postings count (--count)
 
 ..in..
 
@@ -391,8 +392,8 @@ Balance report types
 
 The balance command is quite flexible; here is the full detail on how to
 control what it reports. If the following seems complicated, don't
-worry - this is for advanced reporting, and it does typically take some
+worry - this is for advanced reporting, and it does take time and
-time and experimentation to get clear on all these report modes.
+experimentation to get familiar with all the report modes.
 
 There are three important option groups:
 
@@ -410,6 +411,7 @@ The basic calculation to perform for each table cell. It is one of:
     fluctuations)
 -   --gain : show the unrealised capital gain/loss, (the current valued
     balance minus each amount's original cost)
+-   --count : show the count of postings
 
 Accumulation type
 
@@ -546,20 +548,18 @@ Budget performance in 2017/11/01-2017/12/31:
 ----------------------++----------------------------------------------------
                       ||      0 [              0]       0 [              0] 
 
-This is different from a normal balance report in several ways:
+This is different from a normal balance report in several ways.
+Currently:
 
--   Only accounts with budget goals during the report period are shown,
+-   Accounts with budget goals during the report period, and their
-    by default.
+    parents, are shown.
-
+-   Their subaccounts are not shown (regardless of the depth setting).
--   In each column, in square brackets after the actual amount, budget
+-   Accounts without budget goals, if any, are aggregated and shown as
-    goal amounts are shown, and the actual/goal percentage. (Note:
+    "<unbudgeted>".
-    budget goals should be in the same commodity as the actual amount.)
+-   Amounts are always inclusive (subaccount-including), even in list
-
+    mode.
--   All parent accounts are always shown, even in list mode. Eg assets,
+-   After each actual amount, the corresponding goal amount and
-    assets:bank, and expenses above.
+    percentage of goal reached are also shown, in square brackets.
-
--   Amounts always include all subaccounts, budgeted or unbudgeted, even
-    in list mode.
 
 This means that the numbers displayed will not always add up! Eg above,
 the expenses actual amount includes the gifts and supplies transactions,